We recently published a tutorial on this excellent app, if you missed that you can read it here. Now this app has been updated and optimized for the iPhone 5 and fifth generation iPod Touch. Image processing capabilities have also been increased up to 20 mega pixels/50 MB on the iPhone 5 and iPad 3.
This an excellent app and excellent update, which is free if you have previously purchased this app. If not, you can download it here. It retails for $1.99/£1.49/download.